By Courtney Morris At a Pasadena park, Ricardo Padron and his grandpa sit, observing. Kids fly past, laughing and lunging for each other’s arms in a game of tag. A jogger slows to a walk, mopping sweat with his sleeve. Ducks clump together under a cypress tree, necks tucked, asleep. Years ago, Padron watched his grandpa sketch Looney Tunes cartoons. Now, seated side by side with pencils...